Apparatus for use in the manner of using a blackboard



Dec. 23, 1969 .J. w. NIGHTINGALE APPARATUS FOR USE IN THE MANNER OFUSING A BLACKBOARD Filed Sept. 14, 1966 Inventor United States Patent O3,484,956 APPARATUS FOR USE IN THE MANNER OF USING A BLACKBOARD JackWarwick Nightingale, Liverpool, England, assignor to Pilkington BrothersLimited, Liverpool, England, a corporation of Great Britain Filed Sept.14, 1966, Ser. No. 579,286 Claims priority, application Great Britain,Sept. 21, 1965, 40,214/ 65 Int. Cl. B43] 1/12 US. C]. 35-66 1 ClaimABSTRACT OF THE DISCLOSURE Apparatus having a repeatedly usable writingsurface in the manner of a blackboard is constructed with a panel ofnormally transparent material with parallel obverse and reverse faces,and with a panel of opaque material arranged in contiguity with saidreverse face and presenting a design bearing surface showing through thepanel of transparent material when viewed through the obverse face ofsaid panel, said faces being roughened, the obverse face to render itreceptive to writing and the reverse face to prevent a secondary imageof the writing on the obverse face, and a mounting frame for the panelof normally transparent material and for the opaque panel which delimitsa writing area of the obverse face of the panel of normally transparentmaterial.

This invention relates to apparatus for use in the manner of using ablackboard, and has for its main object to provide a better surface forreceiving inscriptions and information, as well as a background whichcontrasts more clearly with the inscriptions or information, and a furher object is to devise apparatus of the kind referred to which can beused as a screen for a projector.

Apparatus for use in the manner of using a blackboard constructedaccording to the present invention comprises a panel of transparentmaterial, having parallel faces of which the obverse face is rendereddiffuse reflecting and the reverse face is sandblasted to preventformation of a secondary image when information appears on the obverseface, e.g. whenusing a crayon,-and an operatively associated backing ofan opaque material.

The backing preferably consists of a separate backing element and maycarry graph paper markings or other design, but alternatively thebacking may be a suitable opaque coating, (eg. emulsion paint), appliedto the reverse face of the panel of transparent material.

Apparatus according to the invention may be used on easels, in the usualway of supporting blackboards, or may be mounted on a wall support. Inthe latter case the apparatus may include a frame for the panel, and thebacking element may be slidably mounted in the frame behind the panel tofacilitate changing the backing element when required. If the backingelement is the same size as the panel of transparent material, thelatter may have a cut out portion at one edge to allow the thumb to beused in changing the backing element. Alternatively, the backing elementmay be of greater length than the frame, and may have sections ofdifferent surface appearance so that movement thereof in eitherdirection can effect a change of the background. To facilitate thischange of the background the backing element may be wound on rollers oneither side of the panel.

3,484,956 Patented Dec. 23, 1969 Preferably apparatus constructedaccording to the invention comprises a panel of toughened glass,although in some circumstances a panel formed from a transparentindustrial plastic with a sufficiently hard surface can be employed.

When the apparatus is intended to be used as a screen for a projector,the backing associated with the reverse face of the panel may comprise awhite pigment.

In order that the invention may be more clearly understood, a simpleform of construction will now be described, with reference to theaccompanying diagrammatic drawing:

In the drawing a glass panel 1 is shown inset in a frame 2, the front 3of the frame being delineated from the rest of the frame to give easyaccess to the panel, and between the frame part 3 and the obverse faceof the panel is a marginal strip 4 of shock absorbing material, forexample sponge rubber packing material. At the back of the panel 1 andin contiguity therewih is a backing element 5, the face of which isruled horizontally and vertically to simulate the ruling on graph paper.

The obverse face 6 of the panel may be covered with stippling orotherwise sufficiently roughened to render it diffuse reflecting, andthe rear face 7 is roughened, for example by heavily sand-blasting theface, sufliciently to prevent the formation of a secondary image on thereverse face when information is written on the obverse face.

The diffuse reflecting face 6 of the panel may be of sufliciently finetexture so that the inscription may be delineated by using a pen andwater soluble ink.

In the construction described it is possible to remove the front part 3of the frame and then change the opaque backing element, either to showdifferent rulings from those already described, or to substitute asurface suitable for use with a projector.

From the foregoing it will be observed that the diffuse reflectingsurface of the glass panel is facing outwards, or in other words thepanel of non-reflecting glass has the non-reflecting surface facingoutwards, whilst the nature of the rear face of the panel is such as toprevent the formation of a secondary image.

Apparatus according to the invention can constitute notice boards and ithas the advantage that any notice written on the obverse face can easilybe removed by a. damp cloth, thereby providing an eflicient andcontinuously serviceable apparatus of the kind referred to.

Iclaim:

1. Apparatus having a repeatedly usable writing surface in the manner ofa blackboard comprising a panel of normally transparent material withparallel obverse and reverse faces, and a panel of opaque materialarranged in contiguity of said reverse face and representing a designbearing surface showing through the panel of transparent material whenviewed through the obverse face of said panel of normally transparentmaterial, said obverse face being roughened to provide a fine textureddiffusely reflecting surface sufficient to render it receptive towriting as in the normal use of a blackboard, and said reverse facebeing sandblasted to a roughness suffi cient to prevent a secondaryimage of such writing on the obverse face when viewed from the frontthereof but without preventing observation of said surface of the panelof opaque material, a mounting frame for the panel of normallytransparent material and for the opaque panel 5 6 which delimits awriting area of the obverse face of said 1,381,022 6/1921 Schulze 161-35panel of normally transparent material. 1,559,665 11/1925 Beery et a1.35-26 R f Ct d FOREIGN PATENTS e e 500,443 2/1939 Great Britain. UNITEDSTATES PATENTS 823,795 1/1938 France.

7/1896 Mishler 35 66 20,668 1907 Great Britain. 8/1926 35-43 EUGENE R.CAPOZIO, Primary Examiner. 1/1931 Masters 35-63 7/1959 Rohrman 35 65 10HARLAND S. SKOGQUIST, Assrstant Examlner 8/1960 Masters 35-65 US. Cl.X.R. 12/1885 Stewart 35-66 161-35 (5/69) UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent No. '3, ,8 +,956 Dated December 23,1969 Inventor(s) Jack Warwick Nightingale It is certified that errorappears in the above-identified patent and that said Letters Patent: arehereby corrected as shown below:

Column 2, line 53 "of should read --with-- line 53 "represent" shouldread --present-- EEIGNED AND SEM. El?

@EAL} Attest:

WILLIAM SGHUYLER, m Edward M. Fhtcher, Ir.

Comism e atantfl Attestiug Officer

